Surgical treatments for sinusitis and other disorders of the ear, nose and throat have evolved slowly over the years. In current clinical practice, functional endoscopic sinus surgery (FESS) is often used to treat sinusitis or other disorders where drainage of mucous is impaired and/or chronic infections are present. In FESS, an endoscope is inserted into the nose and, under visualization through the endoscope, the surgeon may remove diseased or hypertrophic tissue or bone and may enlarge the ostia of the sinuses to restore normal drainage of the sinuses. FESS procedures can be effective in the treatment of sinusitis and for the removal of tumors, polyps and other aberrant growths from the nose. Other endoscopic intranasal procedures have been used to remove pituitary tumors, to treat Graves disease (i.e., a complication of hyperthyroidism which results in protrusion of the eyes) and surgical repair of rare conditions wherein cerebrospinal fluid leaks into the nose (i.e., cerebrospinal fluid rhinorrhea).
In some instances, sinus and ENT surgery has been performed with the assistance of electronic navigation devices (i.e., “image-guided FESS”). In such image guided surgical procedures, integrated anatomical information is supplied through CT-scan images or other anatomical mapping data taken before the operation. Data from a preoperative CT scan or other anatomical mapping procedure is downloaded into a computer and special sensors known as localizers are attached to the surgical instruments. Thus, using the computer, the surgeon can ascertain, in three dimensions, the precise position of each localizer-equipped surgical instrument at any given point in time. This information, coupled with the visual observations made through the standard endoscope, can help the surgeon to carefully position the surgical instruments to avoid creating CSF leaks and to avoid causing damage to nerves or other critical structures.
Although FESS continues to be the gold standard therapy for severe sinuses, it has several shortfalls. Often patients complain of the post-operative pain and bleeding associated with the procedure, and a significant subset of patients remain symptomatic even after multiple surgeries. Since FESS is considered an option only for the most severe cases (those showing abnormalities under CT scan), a large population of patients exist that can neither tolerate the prescribed medications nor be considered candidates for surgery. Further, because the methodologies to assess sinus disease are primarily static measurements (CT, MRI), patients whose symptoms are episodic are often simply offered drug therapy when in fact underlying mechanical factors may play a significant role. To date, there is no mechanical therapy offered for these patients, and even though they may fail pharmaceutical therapies, no other course of action is indicated. This leaves a large population of patients in need of relief, unwilling or afraid to take steroids, but not sick enough to qualify for surgery.
Some experimental or investigational procedures have also been performed in an effort to treat sinusitis by methods that are less invasive and/or less damaging to ancillary tissues than FESS. For example, European physicians have reported the use of a hydrophilic guidewire and standard PTCA balloon catheter to treat restenosis of surgically created openings in diseased frontal sinuses and stenotic nasal conae. Göttmann, D., Strohm, M., Strecker, E. P., Karlsruhe, D. E., Balloon dilatation of Recurrent Ostial Oclusion of the Frontal Sinus, Abstract No. B-0453, European Congress of Radiology (2001); Strohm, M., Göttmann, D., Treatment of Stenoses of Upper Air Routes by Balloon Dilation, Proceeding of the 83rd Annual Convention of the Association of West German ENT Physicians (1999). The interventions described in this abstract were conducted only on frontal sinuses that had previously been surgically modified and nasal conae. These techniques were not reported to be useable for the treatment of sinus ostia that has not previously been surcically altered or ostia of sinuses other than the easily accessible frontal sinuses. Also, in these reported cases, standard vascular guidewires and angioplasty balloon catheters were used. The techniques described in these publications have not been widely adopted by ENT surgeons, possibly due to the fact that they lacked important novel improvements and modifications as described in this patent application and prior U.S. patent application Ser. Nos. 10/829,917, 10/912,578 and 10/944,270, of which this application is a continuation-in-part.
Other methods and devices for sinus intervention using dilating balloons have been disclosed in U.S. Pat. No. 2,525,183 (Robison) and United States Patent Publication No. 2004/0064150 A1 (Becker). For example, U.S. Pat. No. 2,525,183 (Robison) discloses an inflatable pressure device which can be inserted following sinus surgery and inflated within the sinus. The patent does not disclose device designs and methods for flexibly navigating through the complex nasal anatomy to access the natural ostia of the sinuses. The discussion of balloon materials is also fairly limited to thin flexible materials like rubber which are most likely to be inadequate for dilating the bony ostia of the sinus.
United States patent publication number 2004/0064150 A1 (Becker) discloses balloon catheters formed of a stiff hypotube to be pushed into a sinus. The balloon catheters have a stiff hypotube with a fixed pre-set angle that enables them to be pushed into the sinus. In at least some procedures wherein it is desired to position the balloon catheter in the ostium of a paranasal sinus, it is necessary to advance the balloon catheter through complicated or tortuous anatomy in order to properly position the balloon catheter within the desired sinus ostium. Also, there is a degree of individual variation in the intranasal and paranasal anatomy of human beings, thus making it difficult to design a stiff-shaft balloon catheter that is optimally shaped for use in all individuals. Indeed, rigid catheters formed of hypotubes that have pre-set angles cannot be easily adjusted by the physician to different shapes to account for individual variations in the anatomy. In view of this, the Becker patent application describes the necessity of having available a set of balloon catheters, each having a particular fixed angle so that the physician can select the appropriate catheter for the patient's anatomy. The requirement to test multiple disposable catheters for fit is likely to be very expensive and impractical. Moreover, if such catheter are disposable items (e.g., not sterilizable and reusable) the need to test and discard a number of catheters before finding one that has the ideal bend angle could be rather expensive.
The prior art has not provided catheters, devices, systems and methods that are optimal for minimally invasive treatment of sinusitis, mucocysts, tumors, infections, hearing disorders, fractures, choanal atresia or other conditions of the paranasal sinuses, Eustachian tubes, Lachrymal ducts and other ear, nose, throat or mouth structures.